Night vision systems have been used by the military and law enforcement agencies and include image intensification, thermal imaging, and fusion devices. These devices may be monoculars, binoculars, or goggles and may be hand-held, weapon mounted, or helmet mounted. Night vision systems are typically equipped with one or more image intensifier tubes to allow an operator to see visible wavelength and a small portion of infrared wavelength radiation (approximately 400 nm to approximately 900 nm). They work by collecting the tiny amounts of light that are present but may be imperceptible to our eyes and amplifying it to the point that an operator can easily observe the image.
These systems may be used with weapon mounted aiming and illumination devices to rapidly acquire, identify, and accurately fire on enemy targets for use in daytime and nighttime missions. An optical bench assembly located within a weapon-mounted housing may be used to hold the electrical and optical components. The housing may provide protection from unintended contact or debris. The device may be coupled to the weapon with a suitable attachment mechanism, for example a rail grabber, SLIDE-LOCK® mechanism, or other clamp and generate one or more visible and/or infrared collimated point light beams.
Mechanical adjustors extending through the housing and in contact with the optical bench assembly may be used to steer the optical axis of the light beams relative to the housing. This may enable a user to boresight the light beams to some reference, such as a point of impact of a projectile at a known distance or a barrel mounted boresight laser.
Shortwave infrared illuminators operating around 830 nm have been used in conjunction with night vision systems to flood the scene or area of interest to improve viewability and an infrared aiming/pointing laser also operating around 830 nm have been used to point out an area or person of interest. Since these illuminators and pointers are operating above the visible spectrum (450-750 nm) they cannot be seen with the naked eye. A drawback to these illuminators and pointers is that they can be detected by the enemy if the enemy is equipped with image intensification night vision devices, which operate from approximately 400 nm to approximately 900 nm.